I had to google this to have any idea what it was about. The linked release notes don't explain any of the background, the entirety of the content relevant to the headline is this:
"I've only just tested this and I'm still in disbelief, but it looks like Oculus removed the headset check from the DRM in Oculus Runtime 1.5. As such I've reverted the DRM patch and removed all binaries from previous releases that contained the patch."
Apparently Oculus was testing for a present oculus headset in its runtime, so it was difficult for a third-party devs to build shims to connect other VR hardware to it and enjoy VR games built for oculus.
There were two functions, one that checked whether the occulus headset was connected, and one DRM function. Occulus consolidated those functions into one, in what many assumed to be a move to be able to justify taking down projects like these under the guise of "they break our DRM", which did end up being a talking point against the projects later on.
Apparently they reversed this change now, and you can write a compatibility shim without breaking the DRM once more
which usually means "copy protection" introduced with the goal of protecting the vendor, but which almost always degrades the value to the consumer (sometimes catastrophically, if support by the vendor ends; the nest debacle is probably the most recent example)
Apparently Oculus was testing for a present oculus headset in its runtime, so it was difficult for a third-party devs to build shims to connect other VR hardware to it and enjoy VR games built for oculus.
Mods, I'd suggest changing the URL to something with a better explanation, like http://arstechnica.com/gaming/2016/06/oculus-reverses-course... which includes the above quote in addition to explaining the backstory.